When a trailer from a tractor-trailer rig is being loaded or unloaded at a dock area or the like, the tractor (which will pull or has pulled the trailer) is not normally connected to it. The landing gear of the trailer is lowered to support the front end thereof when the tractor is disconnected. Consequently, the trailer is susceptible to collapse of the trailer landing gear, shifting because of sitting on unlevel ground, and tipping due to loading or unloading by heavy equipment. In order to load and unload the trailer safely, some form of stabilizing device under the trailer front end is required.
Safety devices for use in the environment of the present invention must be maneuverable and easy to operate or they may not be used at all. In the case of a trailer at an unloading or loading dock, an additional problem exists. If the stabilizing device is not maneuverable and easy to operate, the trailer occupies valuable dock space longer than can be tolerated or economically justified. In addition, when a trailer is disconnected from a tractor and the landing gear is down, the trailer front end is several feet from ground level. Normal stabilizing apparatus such as blocks or small hydraulic jacks are not appropriate. The device for stabilizing a trailer front end must be capable of holding substantial loads and in addition be maneuverable into position under the elevated trailer front end. Finally, the jack must be easy to operate.
In order to provide for long operating life, the component parts of the stabilizing jack must be easily assembled and disassembled to permit replacement, repair, maintenance and/or modification of the component parts of the jack.